Mower structure



March 18, c w M -r 2,590,065

MOWER STRUCTURE Original Filed Aug. 16, 1947 2 SHEETS-SI-IEET 1 March18, 1952 c. w. MOTT MOWER STRUCTURE 2 SHEETSSHEET 2 Original Filed Aug.16, 1947 Patented Mar. 18, 1952 MOWER STRUCTURE Carl W. Mott, LakeOzark, Mo., assignor to International Harvester Company, a corporationof New Jersey Original application August 16, 1947, Serial No. 768,993.Divided and this application July 29, 1948, Serial No. 41,344

13 Claims.

This invention concerns grass-cutting mowers of a type employing flailspivotally mounted on a carrier which is rotatable at high speed about ahorizontal axisfor sweeping cutting edges of the flails into the grassfor cutting the same, and relates more particularly to an improved typeof flail and mounting thereof.

This application is a division of my co-pending patent application,Serial No. 768,993, filed August 16, 1947, for Hammer Knife Mower. Saidapplication discloses, in detail, a hammer knife mower which utilizesthe type of flail herein disclosed. It will suffice for the presentdisclosure, therefore, to explain that such a mower, in addition tobeing serviceable for cutting grass of normally-cropped height upon alawn, golf course, or the like, is also capable of cutting abnormallytall grass. Such a mower employs grass-cutting flails pivotally mountedupon a rotatable carrier for swinging radially outwardly from suchcarrier when it is rotated at high speed, thus enabling sharpened endportions of the flails to chop the grass into short pieces irrespectiveof the position of the grass stems at the time of being intercepted byflails. This principle of operation enables the mower to perateanalogously to a hammer mill, the bottom of the mower unit being open,whereby the flails can cooperate with the ground surface in much thesame manner that flails of the hammer mill cooperate with an opposedwall which holds the material that is to be comminuted within reach ofrevolved flails.

Additional information regarding the mower unit in which the inventionherein described and claimed is useful can be had by reference to theaforesaid co-pending patent application.

The general object of this invention is the pro- Q vision of an improvedtype of cutter flail or knife provided with a cutter end portion turnedoutwardly from a pivotally supported shank portion in a manner enablingthe cutter portion to cut a miniature swath while accommodatingcentrifugal discharge of cut grass stems endwise from the flail.

A still further object is the provision in a hammer knife type of mowerof an arrangement wherein flail knives according to the next proceedingobject are arranged in pairs with the shanks of each pair inback-to-back relation and the outwardly turned cutter end portions ofeach pair in diverging relation. This arrangement causes the shank ofeach knife to react against the shank of the knife paired therewith, sothat normally the paired knife shank-S complementally reinforce oneanother but are slightly separable under the force of hard non-cuttableforeign objects which may accidentally lodge between paired shanks, andthis capability of the paired knife shanks minimizes the likelihood oftheir being broken by such foreign objects as sticks, shrubbery stems orother relatively large foreign objects projecting upwardly from theground surface. 1

Other desirable objects inherent in and encompassed by the inventionwill be comprehendable from the ensuing description, the appendedclaims, and the annexed drawings wherein:

Fig. 1 is an elevational view looking edgewise of a flail or knifeembodying a preferred form of the invention.

Fig. 2 is an elevational view looking fiatwise of the knife shown inFig. 1.

Fig. '3 is a transverse sectional view taken on the line 3-3 of Fig. 2.

Fig. 4 is a side elevational view taken edgewise of a modified form offlail or knife.

Fig. 5 is an elevational view taken flatwise of the knife shown in Fig.4.

Fig. 6 is a sectional view taken on the line 6-6 of Fig. 5.

. Fig. 7 is a side elevational view taken edgewise of a third form offlail or knife. 1

Fig. 8 is an elevational view taken fiatwise of the knife shown in Fig.7.

Fig. 9 is a sectional view taken on the line 9-9 of Fig. 8.

Fig. 10 is a front elevational view of the mower unit with only part ofthe hammer knives and of the rotor carrying the same shown in detail,this view being drawn to a reduced scale with respect to that used inthe lower numbered figures.

Fig. 11 is a sectional view taken through the mower unit at the planeindicated by line I Il l in Fig. 10 and also being at a reduced scalesimilarly to Fig. 10.

The flail shown in Figs. 1, 2 and. 3 comprises a rigid strap-like bodyof metal having a straight shank portion 4| and a cutter end portion 39adjacently to a free end 42 of such body. In Fig. 1 it is illustratedthat said end portion 39 of this species of flail extends endwise fromthe straight shank portion 4| while turning outwardly from one of thebroad flat faces of the shank portion to space the free end 42 outwardlyfrom such face. Such outward turning of the end portion 39 is at anacute angle of departure a from the flat faces of the shank 4|, thisangle of departure being sufliciently restricted to accommodatecontrifugal discharge of cut glass axially of the flail along theoutwardly turned section 39 and over the free end 42. An angle a notsubstantially exceeding 65 is preferred for enabling the flail endportion to cut a reasonably wide swath while avoiding accumulation ofgrass stems upon such end portion. The end portion 39 illustrated inFig. 1 has an angle of departure a of 66 which has been found inpractice to give excellent results.

It will also be observed in Figs. 1, 2 and 3 that the outwardly turnedend portion 39 has sharpened opposite edges and that the bevels 43 and44 forming such edges slope from a common broad face of the strap-likebody of the flail to the opposite face thereof. The cutter end portion39 conforms to an are generated about an axis 1), Fig. 1, and subtendsan arc of 66. The angle c included between the shank 4i and the endportion 39 is 105. By sharpening both edges of the outwardly turnedflail end portions, the flails are made reversable, making it possibleto change to a fresh cutting edge for striking the grass after the otherof the edges has become dull or mutilated.

Figs. 4, 5 and 6 illustrate a modified form of cutter flail or knifesubstitutable for that shown in Figs. 1, 2 and 3. This modified form ofknife differs from that of Figs. 1, 2 and 3 in the respect of having astraight outwardly turned portion 39 instead of this portion beingcurved as the corresponding portion 39 of the first embodiment. Acutting edge 44' is formed upon only one edge of this second knifeembodiment, although it is contemplated that the outwardly turner cutterend portion may have its opposite edge sharpened as illustrated in Fig.2. The small angle of departure for the end portion 39 with reference tothe plane of the shank 4! makes a sacrifice in width of swath cuttablethereby, but results in a form of flail less subject to bending whenaccidentally striking a hummock of frozen ground or the like if used forshredding small grain stubble or stalks in the field during late autumnor winter months.

A third embodiment of flail knife, shown in Figs. 7, 8 and 9,distinguishes from the second embodiment in the respect of having acurved section III between the straight flat shank 4|" and the outwardlyturned portion 39". The

straight outwardly turned portion 39" of this embodiment has an angle ofdeparture in the nature of 40 with reference to the plane of the shank 4I. This angle of departure is about the median of a departure anglerange which adapts a straight end portion to cut a fairly wide swath andstill assure satisfactory shedding of grass stems centrifugally from theflail when such stems are moist from rain or early-morning dew.

A mower unit I I illustrating cooperative backto-back use of flailknives of the type described above is shown in Figs. and 11. This unitincludes a rotor casing including end walls l5 and I6 and asemi-cylindrical cover shroud H extending therebetween lengthwise of theunit. Cover shroud H has a front edge [8 and a rear edge [9, therebyproviding an open front side of the rotor chamber beneath the edge l8,an open bottom side for such chamber and an open lower portion of a rearside of the chamber beneath the rear edge 19. A deflector wall 2|, whichis arched transversely, extends lengthwise between the ends walls of theunit and has a front edge 22 disposed adjacently to the rear edge I9 ofthe cover shroud and also adjacently to a circular path traversed by theouter ends of hammer knives or flails 23 during rotation of a carrierstructure 24 upon which such flails are pivotally mounted. This carrierstructure 24 rotates in the direction indicated by the arrow in Fig. 11,whereby the flails are caused. to cut grass or the like of which thestems project upwardly from a ground line 25 and sweep the cut grassstems rearwardly through a discharge space beneath the rear edge IQ ofthe shroud and beneath the arched deflector wall 2i. Disposal of thefront edge of the deflector wall 21 adjacently to the circular pathtraversed by the outer ends of the flails enables this deflector plateto intercept the precipitated grass stems and prevent them from beingcarried upwardly and forwardly beneath the shroud H, which action wouldcause accumulation of such stems in front of the unit so that itsoperation would be impededl When the unit is in operation, it is partlycarried by a long cylindrical ground-engaging roller 26 journaled upon abearing rod 21 extending between the casing end walls [5 and i6 andsecured thereto.

End wall [5 has a bearing unit 28 mounted thereon for rotativelysupporting one end of a rotatable core or shaft 29 of the carrier orrotor 24. Said shaft 29 is hexagonal in cross-section as illustrated inFig. 11. The opposite end of the shaft 29 passes through a hole (notshown) in the end wall I6 and also through a bearing 3| which is carriedby a plate 63 mounted upon such wall. This bearing rotatably supportsthe end of the shaft passing therethrough, and that portion of the shaftprojecting exteriorly of the end wall 16 carries a belt pulley 32 whichis constrained for rotation therewith. Pulley 32 con stitutes part of adriving train for the rotatable flail carrier 24.

The carrier shaft 29 together with elongated plates 33 secured toopposite facets thereof by bolts 34 make up a center structure of thecarrier. Each plate 33 has a row of tongues 35 projecting outwardly fromeach of its opposite longitudinal edges, the tongues in each row beingspaced apart axially. and being bent into circular formations about axesextending endwise of the carrier. Each row of the circularly benttongues 35 slidably receives a pivot rod 36 for pivotal attachment of anassociated row of flails 23. A hole 31 extending through a flange of thebearing 28 and through the mower unit end wall i5 is placed for axialalinement with the rows of circularly curved tongues 35 to facilitateendwise withdrawal and reinsertion of the rods pursuant to assembly orreplacement of the flails 23. In Fig. 2 where one of the flails is shownin elevation, it can be seen that the flails have a hole 38 forreceiving their associated pivot rod 36. Assembly of the flails ontotheir associated pivot rod is accomplished by insertion of the flatflail shank between certain of the axially spaced circularly curvedtongues 35 to place the holes 38 in alinement with the axis of thecircularly bent tongues preparatory to endwise sliding of the rod forcausing it to pass through the hOles 38. In Fig. 10 the flails 23 areshown mounted in pairs, each pair having straight shank portionsarranged in backto-back relation and with outwardly curved portions 39in diverging relation. Each pair of flails 23 constitutes a bladestructure of which the portions 39 constitute cutting blade furcations.It will be noted that these flail portions or furcations 39 divergeradially outwardly with respect to the carrier axis and that suchfurcations also diverge oppositely at angles pf departure from a medianextending perpendicularly from the carrier-extending axis through thecrotch of these furcations during carrier rotation while the flailstructures project radially of the carrier 24 as illustrated in Fig. 11.The diverging portions 39 of the flails cut narrow swathes of grassstems during rotation of the carrier and since the pairs of flails oneach rod 36 are spaced apart axially thereof, the pairs of flails onadjacent rods are disposed out of alinement circumferentially of thecarrier so the space between the circular paths traversed by theoutwardly turned flail end portions on each rod will be traversed by theouter end portions of the flails on adjacent rods during each revolutionof the carrier.

Means for supporting the unit in selective tilted positions about theaxis of ground roller shaft 21 includes a prop rod 9| having anangularly formed end portion 92 disposed in a socket 93 mounted on thecover shroud 11 by a bracket 94.

Having described a limited number of knife flails together with anarrangement showing how they cooperate in back-to-back relation in amower unit, with the view of clearly and concise- 1y illustrating theinvention, I claim:

1. In a hammer knife mower, a rotatable carrier comprising a pivot rodextending axially thereof in radial spaced relation to the rotationalaxis of such carrier, a plurality of pairs of cutter flails pivotallymounted upon and spaced lengthwise of said rod, each of said flailscomprising a rigid strap-like body having a shank portion lying in aplane normal to the rod axis and pivotally connected at an end to therod for pivotal movement within the plane parallel to fiat faces atopposite sides of said shank portion, said body also having a cutter endportion turned outwardly from a face of the associated shank portionwithin the limit of about 65, and the knives of said pairs beingarranged in back-to-back relation with said outwardly turned endportions in diverging relation.

2. A hammer knife mower of the character set forth in claim 1, whereinthere are a plurality of said rods spaced circumferentially of thecarrier, wherein there are spacing means on the rods between said pairsof knives, and said spacing means being effective for maintaining theflails of adjacent of the rods out of registration circumferentially ofthe carrier.

3. The combination set forth in claim 1, wherein the pivoted ends of theshanks contain holes for receiving said rod as an expedient forestablishing the pivotal connection with the rod.

4. In a hammer knife mower, a rotary carrier comprising a centerstructure extending lengthwise and coaxially of the carrier, saidstructure having circumferentially spaced facets extending lengthwisethereof, elongated plates secured to respective of said facets and eachhaving rows of tongues projecting outwardly from opposite longitudinaledges thereof, the tongues in each row being spaced apart axially of thecarrier and being bent into circular formations about an axis extendinglengthwise of the carrier, pivot rods inserted endwise through therespective rows of circular tongues, and cutter flails pivotallyconnected with said rods within the space between certain of thetongues.

5. In a hammer knife grass mower, a rotor casing comprising end wallsand a cover shroud having opposite front and rear edges extendingbetween said end walls, leaving an open front side, an open bottom sideand an open lower portion of a rear side of said casing; a rotor mounted6, in said casing for rotation about an axis extending between said endwalls, hammer knife flails pivotally mounted on said rotor for swingingradially outwardly thereof pursuant to its rotation, the normaldirection of rotation of the carrier being such as to carry the flailsin a path of revolution extending forwardly beneath said shrouddownwardly past the open front side of the casing, backwardly across theopen side of the casing and upwardly across the open rear portion of thecasing; and a deflector wall projecting rearwardly of the rear edge ofsaid shroud to define the upper side of a discharge space leadingrearwardly from the open rear portion of the casing, said deflector wallbeing arched from front to back and having a forward edge disposed inclose proximity to the path traversed by the flails to divert the cutgrass rearwardly through the discharge space.

6. A grass and the like cutting structure of non-cutter bar typecomprising a blade carrier rotatable at high speed about a horizontalaxis spaced upwardly from the ground surface, and a plurality of bladesmounted on said carrier in spaced relation axially thereof andprojecting radially of the carrier axis during such high speed rotation,each blade having a tip inclined toward the axis of the rotatingcarrier, certain successive of said blades axially of the carrier beingin pairs with the tips of the blades in such pairs diverging from eachother outwardly radially of the carrier, said pairs of blades beingarranged in an interrupted helical formation about the carrier axis, andsaid pairs of blades having a proximity axially of the carrier to cutswaths that lap the swaths cut by axially adjacent pairs of blades.

'7. A grass and the like cutting structure of non-cutter bar typecomprising a blade carrier rotatable at high speed about a horizontalaxis spaced upwardly from the ground surface, and a plurality of bladesmounted on said carrier in spaced relation axially thereof andprojecting radially of the carrier axis during such high speed rotation,each blade having a cutting edge portion inclined toward the axis of therotating carrier, certain of the blades in successive contiguity axiallyof the carrier being in pairs with the inclined cutting edge portionsthereof diverging oppositely at angles of departure from a medianextending therebetween radially of the carrier, said angles of departurebeing confined to within approximately 65, said pairs of blades beingarranged in an interrupted helical formation about the carrier axis, andsaid pairs of blades having a proximity axially of the carrier to cutswaths that lap the swaths cut by axially adjacent pairs of blades.

8. A mowing machine of non-cutter bar type comprising a blade carrierfor rotation at high speed about a horizontal axis spaced upwardly fromthe ground surface, and a plurality of blade structures mounted on saidcarrier in spaced relation axially thereof and projecting radially fromthe carrier axis during such high speed rotation, each blade structureincluding cutting blade furcations at its radially outer end, saidfurcations diverging from the carrier axis and diverging oppositely atangles of departure from a median extending perpendicularly from thecarrier axis through the crotch of the furcations, said angles ofdeparture being confined to within approximately 65, said bladestructures being arranged in an interrupted helical formation about thecarrier axis and having relative proximity axially of the carrier to cutswaths that lap the swaths cut by axially adjacent structures.

9. In a hammer knife mower, a rotatable carrier, flail mounting means onsaid carrier in radial spaced relation to the rotational axis thereof, aplurality of pairs of cutter flails pivotally mounted upon said mountingmeans and spaced lengthwise of said carrier, each of said flailscomprising a rigid strap-like body having a shank portion lying in aplane normal to the carrier axis and pivotally connected at one end tothe mounting means for pivotal movement within a plane parallel to fiatfaces at opposite sides of said shank portion, said body also having acutter end portion turned outwardly from a face of the associated shankportion within the limit of about 65, and the knives of said pairs beingarranged in back-to-back relation with said outwardly turned endportions in diverging rela tion.

10. In a hammer knife mower, a rotatable carrier, flail mounting meanson said carrier in radial and circumferential spaced relation to therotational axis thereof, a plurality of pairs of cutter flails pivotallymounted upon said mounting means and spaced lengthwise of said carrier,each of said fiails comprising a rigid strap-like body having a shankportion lying in a plane normal to the carrier axis and pivotallyconnected at one end to the mounting means for pivotal movement within aplane parallel to flat faces at opposite sides of said shank portion,said body also having a cutter end portion turned outwardly from a faceof the associated shank portion within the limit of about 65, and theknives of said pairs being arranged in back-to-back relation with saidoutwardly turned end portions in diverging relation.

11. A cutter flail for a rotary grass mower comprising a rigidstrap-like body having a substantially straight shank portion and acutter end portion extending from one end thereof, said cutter endportion extending out of the plane of said shank portion at a maximumangle of departure in the nature of 65.

12. A cutter flail for a rotary grass mower comprising a rigidstrap-like body having a substantially straight shank portion and acutter end portion extending from one end thereof, said cutter endportion terminating in a free end of said strap-like body and beingcurved out of the plane of the shank portion, the degree in curvature ofsaid end portion being limited so a tangent thereto at the free endforms an angle of departure with the plane of said shank portion withinthe limit of and the tangent to said curvedL end portion at intermediatepoints thereon form angles of departure with said plane progressivelydiminishing in value as a function of the distance of such points fromthe free end.

13. A cutter flail for a rotary grass mower comprising a rigidstrap-like body having a substantially straight shank portion and acutter end portion extending from one end thereof, said cutter endportion being straight and extending out of the plane of said shankportion at an angle of departure in the nature of 40.

CARL W. MOTT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 14,886 Campbell June 22, 1920578,250 I-Iolland-Letz Mar. 2, 1897 1,301,442 Ike Apr. 22, 19191,698,724 Johnston et al Jan. 15, 1929 1,870,932 Sterneman Aug. 9, 19322,034,505 Cline Mar. 17, 1936 2,110,147 Mable Mar. 8, 1938 2,220,342Maga Nov. 5, 1940 2,378,488 Loewe et al June 19, 1945 2,505,089 Baileyet al Apr. 25, 1950 2,509,343 Henderson May 30, 1950 FOREIGN PATENTSNumber Country Date 356,602 Great Britain Sept. 10, 1931

